Machinist vise

ABSTRACT

A machinist vise has a sleeve threaded into a support and carrying an axially extensible hydraulic piston-and-cylinder mechanism which in turn carries a vise jaw engageable with another vise jaw carried on the support. A nut is axially entrained by the sleeve and is rotatable relative thereto while a force-transmitting spindle has one end threaded into the nut and another end engaging a small piston of the hydraulic arrangement, a large piston thereof being engaged by the sleeve. A slip clutch is provided between the nut and the sleeve to couple the two together rotationally until the jaws engage the workpiece, and then decouple the two so that the nut can screw the spindle down to pressurize the hydraulic mechanism at an increased mechanical advantage via the small piston. As the spindle is screwed down it pulls the slip clutch open to insure decoupling of the sleeve and nut.

United States Patent 1191 Riihm I Dec. 18, 1973 MACHINIST VISE S594 10/1955 Germany 269/23 [76] Inventor: GfimellHorst Ram, Muhlstrasse 9, 894,948 10/1953 Germany 269/32 7927 Sontheim Brenz, German l y Primary Examiner-James L. Jones, Jr. Flledl 1971 Assistant Examiner-Joseph T. Zatarga 211 Appl. No.: 189,871 Att0rneyKarl F. Ross [30] Foreign Application Priority Data [57] ABSTRACT 0m. 17, 1970 Germany P 20 51 119.7 A machinist vise has a-Sleeve threaded into a pp Oct. 23, 1970 Germany P70 39 210.8 and y g an extensible hydraulic P and-cylinder mechanism which in turn carries a vise [52] US. Cl 269/23, 269/24, 269/27 j gageable with another vise jaw carried on the 511 1m. (21.... B25b 1/02, B25b l/18 suppert- A nut is axially entrained y the Sleeve and s [58] Field of Search 269/20, 27, 32, 25, rota e e i e thereto while a force-transmitting 269/24, 69,163, 208, 21 1 23, 22, 307 spindle has one end threaded into the nut and another a I end engaging a small piston of the hydraulic arrange- [56]. References Cited 1 ment, a large piston thereof being engaged by the UNITED STATES PATENTS sleeve. A slip clutch is provided between the nutand the sleeve to couple the .two together rotationally until 2 gg t i the jaws engage the workpiece, and then decouple the 3:|47:002 9/1964 'zj: 269/24 two so that the nut can screw the spindle down to 3.400924 9/1968 Arnold I I 269/228 pressurize the hydraulic mechanism at an increased 3,484,094 l2/l969 Arnold... 269/24 mechanical advantage via thesmall piston. As the 3,650,522 3/1972 Wermuth et al 269/2 28 spindle is screwed down it pullsthe slip clutch open to FOREIGN PATENTS, OR APPLICATIONS insure decoupling of the sleeve and nut. 563,735 8/1944 Great Britain 269/23 13 Claims, 3 Drawing Figures 'z-=;,=, .4 8 .24 29 l 3 17a :0

MACHINIST VISE FIELD OF THE INVENTION BACKGROUND OF THE INVENTION A machinist vise often is provided with a clutch ar-- rangement that automatically switches between a highspeed low-mechanical-advantage mode of operation and a low-speed high-mechanical-advantage mode of operation once the workpiece is engaged between the vise jaws. This allows the workpiece to be very tightly clamped, while rapid travel is assured in opening and closing the jaws of the vise.

In one such conventional vise a small hydraulic piston-and-cylinder mechanism is provided as a link between a rotatable spindle threaded in a stationary support and the movable vise jaw. This mechanism has a fluid chamber closed by a pair of pistons, one much larger than the other. This larger piston is engaged by the threaded spindle and the smaller piston is connected via a force-transmitting rod to the displaceable vise jaw so that the vise jaws close rapidly, but once they contact the workpiece the smaller piston is operated creating a substantial mechanical advantage.

In this type of machinist vise the crank or other actuating element continues to move axially even in the high-pressure clamping mode, making it difficult to adjust the vise fully since the crank often gets in the way of other parts of the device when fully advanced.

There is also known an arrangement wherein the crank is rotationally connected to the two pistons which are concentric. Once some resistance has been met a slip clutch disconnects the larger piston from the spindle and the threaded spindle is effective .to drive the smaller piston home. The crank in this arrangement also moves after switchover.

Another known disadvantage of such systems is that the fine or slow-advance phase of the operationis not necessarily cut out after the jaws of the vise are open. Therefore on subsequent use of the vise the slowadvance screw can "only move over a portion of its travel, it not having been fully retracted. There is no way to ascertain in such vises whether the slowadvance screw has been fully retracted; the crank must simply be given a few extra turns after full rapid withdrawal of the jaw. Of course this necessitates fully opening the vise after each clamping operation.

OBJECTS OF THE INVENTION It is therefore an object of the present invention to provide an improved clamping device or vise of the general type described above, i.e., having a slowadvance, high-mechanical-advantage mode of operation and a fast-advance, low-mechanical-advantage mode of operation.

Another object is the provision of such a vise in which the crank remains stationary once the workpiece is engaged and the slow-advance mode of operation is effective. 7

Yet another object is the provision of a vise wherein the extent of high-mechanical-advantage clamping can be visually ascertained. v

A further object is to provide a vise wherein the slowadvance mode of operation always takes place only after the fast-advance mode on closing of the vise, and is completed first on opening of the vise, so that the full length of travel of the displaceable jaw in the slowadvance mode is always at the disposal of the machinist, even when he only opens the vise slightly in order to reposition the workpiece.

SUMMARY OF THE INVENTION The above objects are attained according to the present' invention in a clamping device, preferably a machinist vise, having a sleeve threadedlyreceived in a stationary support and axially displaceable toward a stationary jaw mounted on the support. An axially ex-' pansible hydraulic piston-and-cylinder mechanism is provided on the sleeve and carries a displaceable vise jaw axially engageable with the stationary jaw. A nut adapted to be rotated about the vise axis is axially entrained by thesleeve and is rotatable'relative thereto while a force-transmitting spindle which is nonrotatable relative to the sleeve is threaded at one end into the nut and has another end operatively connected to a small piston of the hydraulic mechanism. A large piston, which surrounds and is concentric with the small piston, is operatively connected to the sleeve. A slip clutch is provided between the sleeve and the nut so that the nut rotates the sleeve and advances the displaceable jaw by means of the large piston until resistance is met, then it decouples them and turns on the spindle to advance the small piston and displace the movable jaw at greatly reduced speed but with a greatly According to another feature of the invention the spindle is formed with an axially elongated transverse hole through whicha pin extends. This p n is received at one end at least in an axial slot in the sleeve to rotationally couple the spindle and sleeve together.

In accordance with yet another feature of this invention the slip clutch is constituted by axially directed teeth formed on confronting surfaces of the nut and a ring or bushing which is rotationally coupled to the spindle and which is urged toward the nut by a spring or .the like.

According to further features of the present invention the sleeve bears on the large piston through a spring or spring packet ofbelleville washers to maintain the chamber under pressure. The outer end of the spindle is advantageously provided with a marking viewable through a port in the sleeve and comparable with indicia thereon to ascertain its position.

DESCRIPTION OF THE DRAWING The above and other objects, features, and advantages will become more readily apparent from the following description, reference being made to the accompanying drawing in which:

FIG. 1 is an axial section through the apparatus according to the present invention;

FIG. 2 is a section taken along line II II of FIG. 1; and

FIG. 3 is an elevational view illustrating a feature of the invention.

SPECIFIC DESCRIPTION The machinist vise according to this invention has a frame 1 screwed to a fixed mounting plate In here mounted in a vertical position but capable of being mounted horizontally, as on a drill press or the like. A movable clamping assembly 2 is displaceable parallel to the plate 1a in the directions indicated by in-line arrows A and B to clamp a workpiece W between a fixed jaw 3 (held in place by screw 33) carried on the housing 1 and a movable jaw 4 carried on a steel slide 2a of the assembly 2.

The position of the slide 2a is determined by a pistonand-cylinder arrangement having a cylinder 5a formed in a cylinder member Sbolted to the slide 2a, with a drain screw 41) provided for emptying and refilling of the cylinder 5a (see my copending patent application, Ser. No. l90,035). A piston 7 is slidable axially in the cylinder 5a and surrounds a piston 6 the piston 7 has an effective surface area equal to around twelve times that of the piston 6 to deplace hydraulic fluid F (here oil) in the cylinder 5a. A gland 8 is provided to prevent leakage around and between the coaxial pistons 6 and 7.

A sleeve 10 is threaded through an arm 11 formed on the frame 1 and bears via springs 12, axially abutting caps 13 and 45, and springs 14a on the piston 7. The springs 12 and 14a, in the form of stacks of belleville washers, are arranged in annular recesses 12a and 14 in the sleeve 10 and between the piston 7 and the cylinder 5. The slide 2a has an axial extension 15 formed with a bore 16 snugly receiving a cylindrical portion of the sleeve 10 between a shoulder 48 formed thereon and a snap ring 34 received therein, leaving a small amount of play P. Thus it should be clear that a rotation of the sleeve 10 in one direction relative to the support 1 will move the jaw 4 in direction A towards the jaw 3 and an opposite rotation will separate these jaws 3 and 4 by restriction of jaw 4 in direction B. As the the sleeve 10 is advanced toward the jaw 3 it bears via the springs 12a, caps 13 and 45, and springs 14a on the piston 7 which in turn bears on the slide'2a to move the jaw 4. The piston 6 is moved in direction A with the piston 7. The fluid F in chamber 5a is kept under pressure by springs 47 surrounding screws 46 received in member 5.

A rod 9 passes axially through the cap 13 and extends into the interior of the hollow sleeve 10, with its lower end bearing on the piston 6 and its upper end bearing on an end of a rod 17 axially slidable in the sleeve 10. Another pin 18 engages the upper end 17a of the rod 17 and is axially couplable with another sleeve or nut 19 carried on the upper end of the sleeve 10. The sleeve 10 and nut 19 are rotationally couplable through a torque coupling shown at 20. At the same time the nut 19 is axially fixed relative to the sleeve 10 by a snap ring 22 on one side and a flange 21 on the other side.

The nut 19 threadedly engages a threaded region 23 of the pin 18 which is prevented from rotating relative to the sleeve 10 by means of a transverse pin 25 passing through a bore 30 in the lower end of the pin 18 and engaging in axial grooves 26 formed in the interior of the sleeve 10 (see FIG. 2). These grooves 26 have an axial length at least equal to the. axial travel of the piston 6.

The torque coupling 20 is formed by axially interengaging V-shaped teeth 29 formed on one end of the sleeve 19 and on the confronting surface of a ring or bushing 27 urged into contact with this sleeve 19 by a spring 28. The bushing 27 is formed with a transverse bore 24 snugly receiving the pin 25 and coupling the spindle 18 to the sleeve 10 for joint rotation. Thus, unless there is undue resistance to rotation, the teeth 29 will couple the sleeves l9 and 10 together through the intermediary of the pin 25 passing through the ring 27. To rotate the sleeve 19 a crank 32 is fitted into a hexagonal socket 31 in the upper end of this sleeve 19.

The upper end of the rod 18 is formed with a circumferential groove 35 visible in relation to a scale 36 formed in a port in the upper end of sleeve 19 (see FIG. 3).

Axially displaceable relative to the upper part 39 of the sleeve 10 is-a ring 37 provided with a pin 38 engageable in axial bores 40 formed in this upper section 39. A key 43 engageable in an axial slot in the ring 37 rotationally couples this ring 37 and the sleeve 19 while a spring-loaded pin 41 is engageable in a pair of axially spaced recesses 42 to retain the ring in an up or down position as described below.

The vise described above functions as follows:

A workpiece W is set between the open jaws 3 and 4 of the device and the crank 32 is rotated in one direction. Rotation of this crank 32 is transmitted by the teeth 29 to the ring 27 and therethrough to the pin 25 which rotates the sleeve 10 relative to its support arm 1 1, thereby advancing this sleeve 10 in the direction A. Since the sleeve 10 bears through springs 12a and 14a and members 13 and 45 on the piston 7, this piston will build up pressure in the cylinder 5a to displace the ja 4 in direction A also.

As soon as the jaws 3 and 4 close on the workpiece W the sleeve 10 will'offer resistance to rotation over and above the nonnal frictional resistance of advance. At this time the spring 28 will compress to allow the teeth 29 to slip relative to-each other, causing the nut 19 to rotate relative to the sleeve 10. This rotation will screw the 'pin 18 in the nut 19, forcing it downwardly. This motion is transmitted by rods 17 and 9 to the piston 6 to advance this smaller-diameter piston into the chamber 5a. Since the effective surface area of piston 6 is only a fraction of that of the piston 7 and since the I pitch of the threads on section 23 is much smaller than that of the threads between the sleeve 10 and the arm 11, the crank 32 is thereby effective with a greatly increased mechanical advantage to clamp the workpiece W between the jaws 3 and 4. Of course the teeth 29 only slip for a very brief time since after only one or two turns of the crank 32 the pin 18 pulls the ring 27 completely out of engagement with the teeth 29 on the sleeve 19. The operator can observe on the scale 36 just how far the pin 18 has moved, which displacement is of course indicative of how tightly the workpiece is clamped. The hole 30 is axially elongated to permit disengagement of the teeth upon the development of a predetermined torque.

The workpiece is released by reverse rotation of the crank 32 which first pulls back the pin 18 in direction B and, when the teeth 29 reengage, rotates the sleeve 10. Thus the piston 6 will always be fully withdrawn when the fast-advance operation is commenced. The

springs 12a and 14a insure that any minor leaks of fluid F are taken up without releasing the workpiece.

Should for some reason the workpiece get wedged between the jaws so tightly that on retraction of the jaw 4 the teeth 29 disengage, the ring 37 can be pushed down so that its pin 38 engages in one of the bores 40 to couple the sleeves l9 and rotationally, thereby making the forcible withdrawal of the jaw 4 possible. This auxiliary rotational coupling is also useful on excessively resilient objects which must be tightly clamped.

The machinist vise described above allows a workpiece to be clamped tightly with great ease. The worker need merely rotate the crank to first advance the jaw 4 at a fast-advance speed with a small mechanical advance and, once the workpiece W is engaged on both sides, the vise automatically and instantaneously switches over to a slow rate of advance with a very great mechani-cal advantage. The slow-advance screw will always be wound fully back automatically at the end of each operation so that the machinist need never worry whether or not he only disposes of part of the effectiveness of this element.

I claim:

1. A clamping device comprising:

a support carrying a stationary jaw;

a sleeve threadedly received in said support and axially di'splaceable towardsaid stationary jaw;

an axially expansible hydraulic piston-and-cylinder mechanism carried on said sleeve and having a large piston and a small piston, said sleeve bearing on said large piston;

a displaceable jaw carried on said mechanism and axially shiftable toward said stationary jaw;

a tubular nut axially coupled with said sleeve and rotatable relative-thereto, said nut extending coaxially into said sleeve a force-transmitting spindle having one end operatively engageable with said small piston and another end axially threadedly received in said tubular nut at a portion thereof within said sleeve said spindle being nonrotatable relative to said sleeve;

and

a slip clutch rotationally coupling said sleeve to said tubular nut and decoupling same after development of a predetermined amount of torque therebetween. I

2. The device defined in claim 1, further comprising a pin, said sleeve being formed with at least one axially extending slot receiving an end of said pin, said spindle being formed with throughgoing transverse hole receiving said pin, whereby said pin' rotationally couples said spindle to said sleeve. q

3. The device defined in claim 2 wherein said clutch comprises a ring engaging said nut and rotationally entrained by said spindle, said ring and said nut having confronting and engaging surfaces formed with interengaging -teeth, said clutch further comprising spring means for urging said ring resiliently into engagement with said nut.

4. The device defined in claim 3 wherein said'ring is formed with a throughgoing transverse'hole receiving said pin, at least one of said holes being sufiiciently axially elongated to permit disengagement'of said teeth on development of said predetermined amount of torque. 5. The device defined in claim 1, further comprising a scale on said nut and a marking on said spindle adjacent said scale, both said scale and said marking being observable from outside said vise.

6. The device defined in claim 1, further comprising means for rotationally coupling said sleeve and said nut even on the amount of torque therebetween exceeding said predetermined amount.

7. The device defined in claim 6 wherein said means for coupling includes a ring axially displaceable and r0- tationally fixed on said sleeve and engageable with said nut, said ring and said nut being provided with mutually interengageable interfitting axially extending formations, whereby axial displacement of said ring toward said nut engages said formations together and rotationally couples said spindle and said nut.

8. The device defined in claim 7 wherein said formations include an axially extending pin.

9. The device defined in claim 1, further comprising a spring between said sleeve and said large piston.

10. A clamping device comprising:

a support carrying a stationary jaw;

a sleeve threadedly received in said support and axially displaceable toward said stationary jaw;

an axially expansible hydraulic piston-and-cylinder mechanism carried on said sleeve and having a largepiston and a small piston, said sleeve bearing on said large piston;

a displaceable jaw carried on said mechanism and axially engageable with said stationary jaw;

a nut axially entrained by said sleeve and rotatable relative thereto;

a force-transmitting spindle having one end operatively engageable with said small piston and another end axially threadedly received in said nut, said spindle being nonrotatable relative to said sleeve;

a slip clutch rotationally coupling said sleeve to said nut and decoupling same after development of a predetermined amount of torque therebetween;

and

apin, said sleeve being formed with at least one axially extending slot receiving an end of said pin, said spindle being formed with a throughgoing transverse hole receiving said pin, whereby said pin rotationally couples said spindle to said sleeve, said .clutch comprising a ring engaging said nut and rotationally entrained by said spindle, said ring and said nut having confronting and engaging surfaces formed with interengaging teeth, said clutch including spring means for urging said ring resiliently into engagement with said nut, said ring being formed with a throughgoing transverse hole receiving said pin, at least one of said holes being sufficiently axially elongated to permit disengagement of said teeth on development of said predetermined amount of torque.

11. The device defined in claim 10, further comprising a scale on said nut and a marking on said spindle adjacent said scale, both said scale and said marking being observable from outside said vise.

12. The device defined in claim 10, further comprising means for rotationally coupling said sleeve and said nut even on the amount of torque therebetween exceeding said predetermined amount.

13. The device defined in claim 10, further comprising a spring between said sleeve and said large piston. 

1. A clamping device comprising: a support carrying a stationary jaw; a sleeve threadedly received in said support and axially displaceable toward said stationary jaw; an axially expansible hydraulic piston-and-cylinder mechanism carried on said sleeve and having a large piston and a small piston, said sleeve bearing on said large piston; a displaceable jaw carried on said mechanism and axially shiftable toward said stationary jaw; a tubular nut axially coupled with said sleeve and rotatable relative thereto, said nut extending coaxially into said sleeve ; a force-transmitting spindle having one end operatively engageable with said small piston and another end axially threadedly received in said tubular nut at a portion thereof within said sleeve , said spindle being nonrotatable relative to said sleeve; and a slip clutch rotationally coupling said sleeve to said tubular nut and decoupling same after development of a predetermined amount of torque therebetween.
 2. The device defined in claim 1, further comprising a pin, said sleeve being formed with at least one axially extending slot receiving an end of said pin, said spindle being formed with throughgoing transverse hole receiving said pin, whereby said pin rotationally couples said spindle to said sleeve.
 3. The device defined in claim 2 wherein said clutch comprises a ring engaging said nut and rotationally entrained by said spindle, said ring and said nut having confronting and engaging surfaces formed with interengaging teeth, said clutch further comprising spring means for urging said ring resiliently into engagement with said nut.
 4. The device defined in claim 3 wherein said ring is formed with a throughgoing transverse hole receiving said pin, at least one of said holes being sufficiently axially elongated to permit disengagement of said teeth on development of said predetermined amount of torque.
 5. The device defined in claim 1, further comprising a scale on said nut and a marking on said spindle adjacent said scale, both said scale and said marking being observable from outside said vise.
 6. The device defined in claim 1, further comprising means for rotationally coupling said sleeve and said nut even on the amount of torque therebetween exceeding said predetermined amount.
 7. The device defined in claim 6 wherein said means for coupling includes a ring axially displaceable and rotationally fixed on said sleeve and engageable with said nut, said ring and said nut being provided with mutually interengageable interfitting axially extending formations, whereby axial displacement of said ring toward said nut engages said formations together and rotationally couples said spindle and said nut.
 8. The device defined in claim 7 wherein said formations include an axially extending pin.
 9. The device defined in claim 1, further comprising a spring between said sleeve and said large piston.
 10. A clamping device comprising: a support carrying a stationary jaw; a sleeve threadedly received in said support and axially displaceable toward said stationary jaw; an axially expansible hydraulic piston-and-cylinder mechanism carried on said sleeve and having a largepiston and a small piston, said sleeve bearing on said large piston; a displaceable jaw carried on said mechanism and axially engageable with said stationary jaw; a nut axially entrained by said sleeve and rotatable relative thereto; a force-transmitting spindle having one end opera-tively engageable with said small piston and another end axially threadedly received in said nut, said spindle being nonrotatable relative to said sleeve; a slip clutch rotationally coupling said sleeve to said nut and decoupling same after development of a predeterMined amount of torque therebetween; and a pin, said sleeve being formed with at least one axially extending slot receiving an end of said pin, said spindle being formed with a throughgoing transverse hole receiving said pin, whereby said pin rotationally couples said spindle to said sleeve, said clutch comprising a ring engaging said nut and rotationally entrained by said spindle, said ring and said nut having confronting and engaging surfaces formed with interengaging teeth, said clutch including spring means for urging said ring resiliently into engagement with said nut, said ring being formed with a throughgoing transverse hole receiving said pin, at least one of said holes being sufficiently axially elongated to permit disengagement of said teeth on development of said predetermined amount of torque.
 11. The device defined in claim 10, further comprising a scale on said nut and a marking on said spindle adjacent said scale, both said scale and said marking being observable from outside said vise.
 12. The device defined in claim 10, further comprising means for rotationally coupling said sleeve and said nut even on the amount of torque therebetween exceeding said predetermined amount.
 13. The device defined in claim 10, further comprising a spring between said sleeve and said large piston. 